1. Field of the Invention
The present invention concerns a pyrotechnic device for launching at least one projectile, of the type including:
a longitudinal launcher tube having a rear end closed by a transverse rear wall and an open front end,
a projectile housed in the tube and adapted to slide longitudinally inside it, towards the front, to be expelled from it via the front end of the tube,
means for defining with the tube and the projectile a rear gas expansion chamber immediately to the rear of the projectile, and
an impulse cartridge adapted on command to develop gas pressure in the rear chamber to cause the expulsion of the projectile via the front end of the tube.
2. Description of the Prior Art
Launcher devices of this type are well known in implementations in which the impulse cartridge is housed in or communicates as directly as possible with the rear chamber, being integrated into either the rear wall of the launcher tube or the rear of the projectile.
The concepts of front and rear are to be understood with reference to the predetermined direction of displacement of the projectile relative to the tube on firing.
The aforementioned previously known disposition of the igniter has a number of drawbacks which can occur separately or cumulatively depending on the type of launcher device.
One of these drawbacks is that it is difficult to produce a preloaded launcher device including the tube and the projectile housed in it but with no igniter, for safe handling and storage. This is because the subsequent fitting of the igniter entails either removing the projectile from the tube and then replacing it, which is a difficult operation and necessarily takes a relatively long time under conditions in which speed may be vital, or a special arrangement of the tube entailing further machining and assembly operations during its manufacture and consequently increasing the overall cost of the device as a whole.
Another drawback is that if the front end of the tube is fitted with a cap to prevent the projectile escaping from the tube during handling or storage and undesirable substances such as water or dust entering the tube, the user does not usually need to remove the cap before firing because the projectile itself expels the cap on entering into contact with it when it is fired, which absorbs some of the energy with which the projectile is expelled and can modify the ballistics of the projectile in an uncontrolled manner.
A further drawback is the great difficulty of disposing a plurality of longitudinally juxtaposed projectiles in the tube for successive firing in a given sequence. This requires a respective impulse cartridge immediately to the rear of each projectile with all the impulse cartridges connected to common control means establishing the required sequence. This is complex and costly.
An object of the present invention is to propose a new design of launcher device of the type indicated in the preamble in order to overcome at least some of the above drawbacks.